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Entity Framework Many To Many exception with inheritance


Entity Framework Many To Many exception with inheritance

By : user2949998
Date : November 17 2020, 04:28 AM
wish helps you If you have 2 Many-to-Many relationships to the same table you need to create 2 separate ICollection properties in order for Entity Framework to fully pick up on what you're trying to do. You can't combine them into one, or else you'll get that lovely error that you're seeing there.
code :


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Changing the type of an (Entity Framework) entity that is part of an inheritance hierarchy

Changing the type of an (Entity Framework) entity that is part of an inheritance hierarchy


By : Ravikant
Date : March 29 2020, 07:55 AM
Any of those help Technically, you can achieve it by using the stored procedure. TPT does not support it.
However, I totally agree with Craig. In classic programming book Design Patterns (Addison-Wesley Professional), authors discuss inheritance versus composition and conclude that one should "favor composition over inheritance."
Entity framework data context does not contain a collection of my entity that uses inheritance. Why?

Entity framework data context does not contain a collection of my entity that uses inheritance. Why?


By : Zaneer
Date : March 29 2020, 07:55 AM
wish of those help http://mosesofegypt.net/post/Inheritance-and-Associations-with-Entity-Framework-Part-3.aspx
This article describes how to extend an entity and add a navigation property yourself. Scroll to the "Build Specific Department Query" header. This is what I was after, eliminating the requirement of using .OfType().
Entity framework exception when saving more than 1 object in a 1 to many relationship, when we have inheritance

Entity framework exception when saving more than 1 object in a 1 to many relationship, when we have inheritance


By : Soshell
Date : March 29 2020, 07:55 AM
I wish this help you You should delete the 0 - 0..1 relation in the diagram. It is replaced by the inheritance that you have added. Notice there are no corresponding Nav properties.
And as it turns out this was the actual error.
Entity Framework generic entity inheritance id error

Entity Framework generic entity inheritance id error


By : user6924900
Date : March 29 2020, 07:55 AM
around this issue Part 2 problem, which continues from here: EntityFramework Core - Update record fails with DbUpdateConcurrencyException , The problem is that the call
code :
builder.Entity<EntityMinimum>()
foreach (var entityType in modelBuilder.Model.GetEntityTypes())
{
    if (typeof(EntityMinimum).IsAssignableFrom(entityType.ClrType))
        entityType.FindProperty("Version").IsConcurrencyToken = false;
}
Log DbContext.SaveChanges Exception to the database in Entity Framework/Entity Framework Core

Log DbContext.SaveChanges Exception to the database in Entity Framework/Entity Framework Core


By : Auwe Abellonar
Date : March 29 2020, 07:55 AM
will be helpful for those in need In Entity framework Core, I have solved the problem easily using EF-Core Transaction
code :
try
{
    _unitOfWork.Repository<Product>().InsertEntity(product);
     await _unitOfWork.SaveChangesAsync();//This throws exception due the model validation failure
}
catch (Exception exception)
{
    ExceptionModel exceptionModel = new ExceptionModel();

    string connectionString = _configuration.GetConnectionString("MyConnection");

    var options = new DbContextOptionsBuilder<MyDbContext>()
                .UseSqlServer(new SqlConnection(connectionString))
                .Options;

    using (var dbContext = new MyDbContext(options))
    {
         using (var transaction = dbContext.Database.BeginTransaction())
         {
             try
             {
                   dbContext.Exceptions.Add(exceptionModel);
                   await dbContext.SaveChangesAsync();
                   transaction.Commit();
             }
             catch (Exception e)
             {
                 Console.WriteLine(e);
                 throw;
             }
         }
     }
}
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